JP3413484B2 - Laser annealing equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a laser annealing apparatus.

[0002]

2. Description of the Related Art In the field of semiconductor manufacturing, after implanting ions into a semiconductor substrate, the purpose is to remove the crystal strain (lattice defect) caused by the ion implantation or to activate the implanted ions. Heat treatment (annealing) of the semiconductor substrate is performed. As one of the devices for performing such annealing, there is a laser annealing device for performing annealing using a laser beam.

Laser annealing equipment is also used to melt and recrystallize amorphous silicon thin films for the purpose of making polycrystalline silicon thin films.

A conventional laser annealing apparatus is a laser oscillator (excimer laser, etc.) for generating a laser beam.
And an optical system (such as a cylindrical lens) for shaping the laser beam from the laser oscillator.

[0005]

When annealing is performed by using a laser annealing device, a precise rectangular beam having a relatively small irradiation area and a coarse irradiation area having a relatively large irradiation area are provided according to the precision required for the processing. It is necessary to properly use a long beam (which is called a long beam for the sake of convenience in relation to the rectangular beam, but its shape is close to a rectangle). However, since the conventional laser annealing apparatus can irradiate only the laser beam having one shape defined by the optical system, in order to properly use the two types of laser beams, the optical systems different from each other are used. It is necessary to prepare two laser annealing devices equipped with. Therefore, there is a problem that a large cost and a large footprint are required to properly use the two types of laser beams by using the conventional laser annealing apparatus.

The present invention provides a laser annealing apparatus capable of irradiating a processing substrate with two laser beams having different shapes, and an object thereof is to reduce the cost and the footprint.

[0007]

According to the present invention, a laser oscillator for generating a laser beam for irradiating a processing substrate, and the laser beam emitted from the laser oscillator are shaped and applied to the processing substrate. In a laser annealing device including an optical system, as the optical system, two systems of optical systems that shape the laser beam into mutually different shapes are provided, and the laser is selectively applied to these two systems of optical systems. A laser annealing apparatus is provided, which is provided with an optical path switching means for making a beam incident, and irradiates the processing substrate with the laser beam that has passed through one of the two optical systems.

Specifically, in the present invention, the shape of the laser beam that has passed through one of the two optical systems is rectangular.
It is characterized in that the shape of the laser beam that has passed through the other optical system is an elongated shape having a longer side than the longer side of the rectangle. Further, in the present invention, the optical path switching means has a total reflection mirror and a pneumatic cylinder for directly moving the total reflection mirror, and the total reflection mirror is on the optical path of a laser beam emitted from the laser oscillator. It is characterized in that the laser beam is selectively made incident on one of the two optical systems by advancing / retreating.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. This laser annealing device includes a laser oscillator 11 that generates a laser beam, a rectangular beam optical system 12 and a long beam optical system 13 that shapes the laser beam from the laser oscillator 11, an optical path switching mirror 14, and an optical path switching mirror. 1
A pneumatic cylinder 15 for driving the laser beam 4 into and out of the optical path of the laser beam emitted from the laser oscillator 11,
And a plurality of mirrors 16a, 16 and 16c.

The laser oscillator 11 is, for example, an excimer laser oscillator that oscillates a laser beam in the ultraviolet region. The laser oscillator 11 includes a long beam optical system 13
A laser beam is emitted toward.

The optical path switching mirror 14 is the laser oscillator 1
It is a mirror that totally reflects the laser beam from 1. The optical path switching mirror 14 can be moved in and out of an optical path connecting the laser oscillator 11 and the long beam optical system 13 by a pneumatic cylinder 15. That is, the pneumatic cylinder 15 causes the optical path switching mirror 14 to enter the optical path of the laser beam emitted from the laser oscillator 11 and directed to the long beam optical system 13, and retracts the optical path switching mirror 14 from there. Let

When the optical path switching mirror 14 is moved into the optical path by the pneumatic cylinder 15, the laser beam is reflected by the optical path switching mirror 14 and changes its traveling direction. Then, the laser beam reflected by the optical path switching mirror 14 passes through the mirror 16a and the rectangular beam optical system 1 is used.
Incident on 2. Conversely, when the optical path switching mirror 14 is retracted from the optical path by the pneumatic cylinder 15, the laser beam goes straight and enters the long beam optical system 13.

The rectangular beam optical system 12 has a condenser lens (not shown). This condenser lens condenses the laser beam that has entered the rectangular beam optical system 12,
A laser beam having a rectangular cross section (including a square) is emitted. The laser beam emitted from the rectangular beam optical system 12 is reflected by the mirror 16b and is applied to the processing substrate 17.

On the other hand, the long beam optical system 13 has a cylindrical lens (not shown). Then, the cylindrical lens collects the incident laser beam in the uniaxial direction and emits the laser beam having a long cross section (linear shape). Here, by combining this cylindrical lens with another cylindrical lens, not only the width of the linear laser beam but also its length can be adjusted. The long hi-beam optical system 13 is
It may have a homogenizer instead of the cylindrical lens. The laser beam emitted from the long beam optical system 13 is reflected by the mirror 16c and applied to the processing substrate 17.

With the above structure, in the laser annealing apparatus according to the present embodiment, the optical path switching mirror is moved in or out of the optical path so that either the rectangular beam optical system or the long beam optical system can be used. , A laser beam can be incident. That is, according to this laser annealing apparatus, a rectangular beam or a long beam can be selectively used according to the purpose of processing. Moreover, since it is the same as the conventional laser annealing device except that it has an optical system for a rectangular beam and an optical system for a long beam, and that it has an optical path switching mirror and the like, two laser annealing devices are required. The cost can be reduced as compared with the case of using. Further, by arranging the rectangular beam optical system and the long beam optical system in the vertical direction, the footprint can be made almost the same as that of the conventional laser annealing device.

In an actual laser annealing apparatus, an attenuator for adjusting the beam intensity, a correction optical system for correcting the divergence angle of the laser beam, a uniform optical system for equalizing energy distribution, and a beam shaping. A beam expander or the like is provided as necessary, and these are provided, for example, between the laser oscillator 11 and the insertion position of the optical path switching mirror 14.

In the present embodiment, the optical path switching mirror 14 is driven by the pneumatic cylinder 15.
The present invention is not limited to this, and a motor or the like may be used. Further, the optical path switching mirror 14 does not necessarily have to be directly moved, but may be rotated.

In this embodiment, the processing substrate holding mechanism and the like are not described, but normally the processing substrate is
The substrate is held by a substrate holder or the like in the process chamber and placed under an inert gas atmosphere. Then, the laser beam is emitted through a window provided in the process chamber.

[0020]

According to the present invention, two optical systems are provided as the optical system of the laser annealing apparatus, and the optical path switching means for selectively making the laser beam from the laser oscillator incident on these two optical systems is provided. Thus, it is possible to obtain a laser annealing device capable of selectively using two types of laser beams, and it is possible to realize cost reduction and footprint reduction.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a laser annealing device according to an embodiment of the present invention.

[Explanation of symbols]

11 Laser oscillator 12 Optical system for rectangular beam 13 Long beam optical system 14 Optical path switching mirror 15 Pneumatic cylinder 16a, 16b, 16c mirror 17 Processed substrate

Claims (3)

(57) [Claims] 1. A laser annealing apparatus comprising: a laser oscillator that generates a laser beam to be irradiated onto a processing substrate; and an optical system that shapes the laser beam emitted from the laser oscillator and irradiates the processing substrate. As the optical system, two optical systems for shaping the laser beam into different shapes are provided, and an optical path switching means for selectively making the laser beam incident on the two optical systems is provided. A laser annealing apparatus, wherein the laser beam that has passed through one of two optical systems is applied to the processing substrate. 2. A long laser beam having one of the two optical systems having a rectangular shape and a laser beam having the other optical system having a long side longer than the long side of the rectangle. The laser annealing device of claim 1, wherein the laser annealing device has a shape. 3. The optical path switching means includes a total reflection mirror,
A pneumatic cylinder for directly moving the total reflection mirror, and by moving the total reflection mirror in and out of the optical path of the laser beam emitted from the laser oscillator, the laser beam has two optical systems. 3. The light is selectively made incident on either of the above.
Laser annealing equipment.